(a) The purchase of all supplies, equipment, and materials,
when the expenditure required exceeds fifty thousand dollars
($50,000), shall be by contract let to the lowest responsible bidder.
(b) The construction of facilities and works, when the expenditure
required exceeds three thousand dollars ($3,000), shall be by
contract let to the lowest responsible bidder. Notwithstanding the
preceding sentence, the district may elect to have this construction
be governed by Article 3 (commencing with Section 22030) of Chapter
2.
(c) Notice requesting bids shall be published at least once in a
newspaper of general circulation, which publication shall be made at
least 10 days before bids are received. The board may reject any and
all bids and readvertise in its discretion.

All bids for construction work shall be presented under
sealed cover and shall be accompanied by one of the following forms
of bidder's security:
(a) Cash.
(b) A cashier's check made payable to the district.
(c) A certified check made payable to the district.
(d) A bidder's bond executed by an admitted surety insurer, made
payable to the district.
Upon an award to the lowest bidder, the security of an
unsuccessful bidder shall be returned in a reasonable period of time,
but in no event shall that security be held by the district beyond
60 days from the time the award is made.

If after rejecting bids the board determines and declares by
a four-fifths vote of all its members that in its opinion the
supplies, equipment and materials may be purchased at a lower price
in the open market, the board may proceed to purchase the supplies,
equipment and materials in the open market without further observance
of the provisions requiring contracts, bids or notice.

In case of an emergency, the board may, by resolution passed
by a four-fifths vote of all its members, declare and determine that
public interest and necessity demand the immediate expenditure of
public money to safeguard life, health, or property, and thereupon
proceed to expend or enter into a contract involving the expenditure
of any sum needed in the emergency without observance of the
provisions requiring contracts, bids, or notice. If notice for bids
to let contracts will not be given, the board shall also comply with
Chapter 2.5 (commencing with Section 22050).